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Static moment of a cut off part of the section relative to the
neutral axis
2
2
 h  1 h  bh  4y 

*
*
*
S  F y  b  y   y  1 .
z c      2 
 2  2 2  8  h 

Substituting the considered values in Zhuravsky’s formula, we
obtain:
2
3 Q  4y 
y
   1 2  . (6.19)
2 bh  h 

Figure 6.11

The analysis of the formula (6.19) shows that the tangential
stresses across the section height change by law of quadratic
parabola (fig. 6.11, b). At the most distant points from the neutral
axis (when y   h / 2 ) we have   ; the neutral line (with y  )
0
0
will be
3 Q
   
max .
2 bh
Under the action of tangential stresses the shear deformation
occurs, leading to the curvature of the beam cross-sections. The
nature of the curvature is shown in fig. 6.11 c. The more detailed
study of these issues shows that the distortion of a plane shape of
cross-sections because of shear deformation has no significant

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